Stability analysis of Negative Impedance Converter and improving the bandwidth of electrically small antennas

Abstract

Negative Impedance Converter (NIC) have received much attention to improve the restriction of antenna gain-bandwidth tradeoff relationship. However, a significant problem with NIC is the potential instability of unwanted oscillation due to the presence of positive feedback. For solving this problem, we propose a NIC circuit technique which is stable and improves bandwidth of electrically small antennas.